My son owns half of the house. Will we loose our home if I file for bankruptcy?

This is for Arizona. Six months ago, following my divorce, I had good credit and purchased a house with my son. Home was short sale for $185k. I now need to file bankruptcy. I satisfy the means test for Chapter 7. I want to keep my house and my car. The current value is $1600. Arizona does have exemptions, $5000 for car and $150k for house. We put 3.5% down and home appraised for $195k so the equity in the home is about $16k. But it is $45k over the homestead exemption limit. However, my son owns half. Will we get to keep the house? Will my bankruptcy hurt my son? Will he loose his interest in the house? My debt is approximately $50k. My yearly income is about $10,400. My understanding is that my alimony and child support is also exempted. Is that true?